/*
 * Copyright 2014-2023 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package de.codecentric.boot.admin.server.services;

import java.time.Duration;

import com.github.tomakehurst.wiremock.WireMockServer;
import com.github.tomakehurst.wiremock.core.Options;
import com.github.tomakehurst.wiremock.http.Fault;
import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.springframework.boot.actuate.endpoint.ApiVersion;
import org.springframework.http.MediaType;
import reactor.core.publisher.Mono;
import reactor.test.StepVerifier;

import de.codecentric.boot.admin.server.domain.entities.EventsourcingInstanceRepository;
import de.codecentric.boot.admin.server.domain.entities.Instance;
import de.codecentric.boot.admin.server.domain.entities.InstanceRepository;
import de.codecentric.boot.admin.server.domain.events.InstanceStatusChangedEvent;
import de.codecentric.boot.admin.server.domain.values.Endpoint;
import de.codecentric.boot.admin.server.domain.values.InstanceId;
import de.codecentric.boot.admin.server.domain.values.Registration;
import de.codecentric.boot.admin.server.eventstore.ConcurrentMapEventStore;
import de.codecentric.boot.admin.server.eventstore.InMemoryEventStore;
import de.codecentric.boot.admin.server.web.client.InstanceWebClient;

import static com.github.tomakehurst.wiremock.client.WireMock.aResponse;
import static com.github.tomakehurst.wiremock.client.WireMock.get;
import static com.github.tomakehurst.wiremock.client.WireMock.ok;
import static com.github.tomakehurst.wiremock.client.WireMock.okForContentType;
import static com.github.tomakehurst.wiremock.client.WireMock.okJson;
import static com.github.tomakehurst.wiremock.client.WireMock.status;
import static com.github.tomakehurst.wiremock.stubbing.Scenario.STARTED;
import static de.codecentric.boot.admin.server.web.client.InstanceExchangeFilterFunctions.retry;
import static de.codecentric.boot.admin.server.web.client.InstanceExchangeFilterFunctions.rewriteEndpointUrl;
import static de.codecentric.boot.admin.server.web.client.InstanceExchangeFilterFunctions.timeout;
import static java.util.Collections.emptyMap;
import static java.util.Collections.singletonMap;
import static org.assertj.core.api.Assertions.assertThat;

class StatusUpdaterTest {

	// @Rule
	public final WireMockServer wireMock = new WireMockServer(Options.DYNAMIC_PORT);

	private StatusUpdater updater;

	private ConcurrentMapEventStore eventStore;

	private InstanceRepository repository;

	private Instance instance;

	@BeforeAll
	static void setUp() {
		StepVerifier.setDefaultTimeout(Duration.ofSeconds(5));
	}

	@AfterAll
	static void tearDown() {
		StepVerifier.resetDefaultTimeout();
	}

	@BeforeEach
	void setup() {
		this.wireMock.start();
		this.eventStore = new InMemoryEventStore();
		this.repository = new EventsourcingInstanceRepository(this.eventStore);
		this.instance = Instance.create(InstanceId.of("id"))
			.register(Registration.create("foo", this.wireMock.url("/health")).build());
		StepVerifier.create(this.repository.save(this.instance)).expectNextCount(1).verifyComplete();

		this.updater = new StatusUpdater(this.repository,
				InstanceWebClient.builder()
					.filter(rewriteEndpointUrl())
					.filter(retry(0, singletonMap(Endpoint.HEALTH, 1)))
					.filter(timeout(Duration.ofSeconds(2), emptyMap()))
					.build(),
				new ApiMediaTypeHandler());
	}

	@AfterEach
	void teardown() {
		this.wireMock.stop();
	}

	@Test
	void should_change_status_to_down() {
		String body = "{ \"status\" : \"UP\", \"details\" : { \"foo\" : \"bar\" } }";
		this.wireMock.stubFor(
				get("/health").willReturn(okForContentType(ApiVersion.LATEST.getProducedMimeType().toString(), body)
					.withHeader("Content-Length", Integer.toString(body.length()))));

		StepVerifier.create(this.eventStore)
			.expectSubscription()
			.then(() -> StepVerifier.create(this.updater.updateStatus(this.instance.getId())).verifyComplete())
			.assertNext((event) -> {
				assertThat(event).isInstanceOf(InstanceStatusChangedEvent.class);
				assertThat(event.getInstance()).isEqualTo(this.instance.getId());
				InstanceStatusChangedEvent statusChangedEvent = (InstanceStatusChangedEvent) event;
				assertThat(statusChangedEvent.getStatusInfo().getStatus()).isEqualTo("UP");
				assertThat(statusChangedEvent.getStatusInfo().getDetails()).isEqualTo(singletonMap("foo", "bar"));
			})
			.thenCancel()
			.verify();

		StepVerifier.create(this.repository.find(this.instance.getId()))
			.assertNext((app) -> assertThat(app.getStatusInfo().getStatus()).isEqualTo("UP"))
			.verifyComplete();

		StepVerifier
			.create(this.repository.computeIfPresent(this.instance.getId(),
					(key, instance) -> Mono.just(instance.deregister())))
			.then(() -> StepVerifier.create(this.updater.updateStatus(this.instance.getId())).verifyComplete())
			.thenCancel()
			.verify();

		StepVerifier.create(this.repository.find(this.instance.getId()))
			.assertNext((app) -> assertThat(app.getStatusInfo().getStatus()).isEqualTo("UNKNOWN"))
			.verifyComplete();
	}

	@Test
	void should_not_change_status() {
		String body = "{ \"status\" : \"UNKNOWN\" }";
		this.wireMock.stubFor(
				get("/health").willReturn(okJson(body).withHeader("Content-Type", Integer.toString(body.length()))));

		StepVerifier.create(this.eventStore)
			.expectSubscription()
			.then(() -> StepVerifier.create(this.updater.updateStatus(this.instance.getId())).verifyComplete())
			.expectNoEvent(Duration.ofMillis(100L))
			.thenCancel()
			.verify();
	}

	@Test
	void should_change_status_to_up() {
		this.wireMock.stubFor(get("/health").willReturn(ok()));

		StepVerifier.create(this.eventStore)
			.expectSubscription()
			.then(() -> StepVerifier.create(this.updater.updateStatus(this.instance.getId())).verifyComplete())
			.assertNext((event) -> assertThat(event).isInstanceOf(InstanceStatusChangedEvent.class))
			.thenCancel()
			.verify();

		StepVerifier.create(this.repository.find(this.instance.getId()))
			.assertNext((app) -> assertThat(app.getStatusInfo().getStatus()).isEqualTo("UP"))
			.verifyComplete();
	}

	@Test
	void should_change_status_to_down_with_details() {
		String body = "{ \"foo\" : \"bar\" }";
		this.wireMock
			.stubFor(get("/health").willReturn(status(503).withHeader("Content-Type", MediaType.APPLICATION_JSON_VALUE)
				.withHeader("Content-Length", Integer.toString(body.length()))
				.withBody(body)));

		StepVerifier.create(this.eventStore)
			.expectSubscription()
			.then(() -> StepVerifier.create(this.updater.updateStatus(this.instance.getId())).verifyComplete())
			.assertNext((event) -> assertThat(event).isInstanceOf(InstanceStatusChangedEvent.class))
			.thenCancel()
			.verify();

		StepVerifier.create(this.repository.find(this.instance.getId())).assertNext((app) -> {
			assertThat(app.getStatusInfo().getStatus()).isEqualTo("DOWN");
			assertThat(app.getStatusInfo().getDetails()).containsEntry("foo", "bar");
		}).verifyComplete();
	}

	@Test
	void should_change_status_to_down_without_details_incompatible_content_type() {
		this.wireMock.stubFor(get("/health").willReturn(status(503)));

		StepVerifier.create(this.eventStore)
			.expectSubscription()
			.then(() -> StepVerifier.create(this.updater.updateStatus(this.instance.getId())).verifyComplete())
			.assertNext((event) -> assertThat(event).isInstanceOf(InstanceStatusChangedEvent.class))
			.thenCancel()
			.verify();

		StepVerifier.create(this.repository.find(this.instance.getId())).assertNext((app) -> {
			assertThat(app.getStatusInfo().getStatus()).isEqualTo("DOWN");
			assertThat(app.getStatusInfo().getDetails()).containsEntry("status", 503)
				.containsEntry("error", "Service Unavailable");
		}).verifyComplete();
	}

	@Test
	void should_change_status_to_down_without_details_no_body() {
		this.wireMock.stubFor(
				get("/health").willReturn(status(503).withHeader("Content-Type", MediaType.APPLICATION_JSON_VALUE)));

		StepVerifier.create(this.eventStore)
			.expectSubscription()
			.then(() -> StepVerifier.create(this.updater.updateStatus(this.instance.getId())).verifyComplete())
			.assertNext((event) -> assertThat(event).isInstanceOf(InstanceStatusChangedEvent.class))
			.thenCancel()
			.verify();

		StepVerifier.create(this.repository.find(this.instance.getId())).assertNext((app) -> {
			assertThat(app.getStatusInfo().getStatus()).isEqualTo("DOWN");
			assertThat(app.getStatusInfo().getDetails()).containsEntry("status", 503)
				.containsEntry("error", "Service Unavailable");
		}).verifyComplete();
	}

	@Test
	void should_change_status_to_offline() {
		this.wireMock.stubFor(get("/health").willReturn(aResponse().withFault(Fault.EMPTY_RESPONSE)));

		StepVerifier.create(this.eventStore)
			.expectSubscription()
			.then(() -> StepVerifier.create(this.updater.updateStatus(this.instance.getId())).verifyComplete())
			.assertNext((event) -> assertThat(event).isInstanceOf(InstanceStatusChangedEvent.class))
			.thenCancel()
			.verify();

		StepVerifier.create(this.repository.find(this.instance.getId())).assertNext((app) -> {
			assertThat(app.getStatusInfo().getStatus()).isEqualTo("OFFLINE");
			assertThat(app.getStatusInfo().getDetails()).containsKeys("message", "exception");
		}).verifyComplete();

		StepVerifier.create(this.updater.updateStatus(this.instance.getId())).verifyComplete();
	}

	@Test
	void should_retry() {
		this.wireMock.stubFor(get("/health").inScenario("retry")
			.whenScenarioStateIs(STARTED)
			.willReturn(aResponse().withFixedDelay(5000))
			.willSetStateTo("recovered"));
		this.wireMock.stubFor(get("/health").inScenario("retry").whenScenarioStateIs("recovered").willReturn(ok()));

		StepVerifier.create(this.eventStore)
			.expectSubscription()
			.then(() -> StepVerifier.create(this.updater.updateStatus(this.instance.getId())).verifyComplete())
			.assertNext((event) -> assertThat(event).isInstanceOf(InstanceStatusChangedEvent.class))
			.thenCancel()
			.verify();

		StepVerifier.create(this.repository.find(this.instance.getId()))
			.assertNext((app) -> assertThat(app.getStatusInfo().getStatus()).isEqualTo("UP"))
			.verifyComplete();
	}

}
